Fin-stabilized projectile for launchers, mortars and the like

ABSTRACT

A fin-stabilized projectile for launchers, mortars and the like includes an annular tail member secured to the rear end of the projectile body with a fin assembly secured to the exterior of the tail member. A propulsion charge powder cartridge is mounted in the interior of the annular tail member and comprises an externally threaded element secured in the rear end of the annular tail member with a sleeve extending forwardly therein upon which an elongated tubular powder member is mounted.

waited gtates Patent H 1 [11] 3.79363 Donner Feb. 5,- 11974 FIN-STABILIZEB9 PROJE (IE FOR LAUNCHERS, MORTARS AND LII Liljegre n 102/492 FOREIGN PATENTS OR APPLICATIONS 496,792 12/1938 Great Britain 102/29 M Primary Examiner-Benjamin A. Borchelt Assistant Examiner-J. V. Doramus Attorney, Agent, or FirmMarkva, Smith et al.

57 SACT therein upon which an elongated tubular powder member is mounted.

4 9 Ciaims, 3 Drawing Figures MET 2 MY 2.

FIG. 3'

FIN-STABTLTZED PRUJECTHLE FOR LAUNCHERS, MORTARS AND THE LHK E This invention relates to a fin-stabilized projectile for launchers, mortars and the like and more particularly to the tail member of the projectile which serves both to support the fin assembly and to contain a propulsion charge powder cartridge.

fin-stabilized projectiles normally comprise an annular tail member upon which the fin assembly is mounted and within which the propulsion charge is located. Perforations are provided in the wall of the annular tail member between the plurality of fins permitting the gases emitted following firing of the charge to be released. A disadvantage of this arrangement is that the size of the propulsive charge is limited since the area provided within the tail member for containing the propulsion charge is only coextensive with that part of the tail member supporting the fin assembly. The propulsion charge in the form of a cartridge contains the detonator as well as the powder charge, and since the length of the cartridge is limited to that portion of the tail member carrying the fin assembly the initial or starting speed of the projectile upon firing the charge is correspondingly limited.

An object of the present invention is to provide a fin stabilized projectile in which greater amounts of powder charge can be accommodated whereby the starting speed of th projectile can be increased.

A further object of the invention is to provide a tail member for the projectile which is capable of accommodating a tubular powder member of greater length than was previously possible whereby the starting speed of the projectile can be increased.

The various features and advantages-of the invention will become apparent in the following detailed description of an embodiment as depicted in the drawings in which:

FIG. 1 is a side view partly in section of the rear portion of a fin-stablized projectile according to the invention;

FIG. 2 is a side view partly in section of the rear portion of a projectile in accordance with another embodiment of the invention; and

FIG. 3 is a more detailed side view partly in section of the powder charge cartridge shown in FIG. 1.

The projectile body 1 of the fin-stabilized projectile is provided at the rear end with an annular tail member 2 which may be conveniently internally threaded at the forward end and screwed onto an externally threaded part 1a at the rear of the body 1. A fin assembly 3 comprising a plurality of radially extending fins is mounted on the rear portion of the annular tail member 2. A plurality of perforations or holes 4 is provided in the wall of the annular tail member forwardly of the fin assembly to permit release of gases generated during discharge of the explosive contained therein.

A powder cartridge shown generally at 5 for propelling the projectile is housed interiorally of the annular tail member 2. The powder cartridge includes an annu lar plug 6 having external helical threads 7 whereby the plug may be screwed into the rear end of the annular tail member 2 which contains corresponding internal helical threads.

An annular seat is provided at the forward end of the plug 6, and one end of an annular carrier sleeve ll having an outwardly extended angled portion 14 is located in the annular seat 15 with the angled portion 14 5 l1, and a detonator 9 is positioned internally and at the rear end of the plug 6.

An elongated tubular powder member M) is supported internally on the carrier sleeve Ill and projects forwardly to a position adjacent the forward end of the 10 annular tail member 2. The step 13 serves to limit rearward movement of the tubular powder member it) beyond a predetermined point. The tubular powder member lid advantageously is at least long enough for its forward end 10a to reach at least to the forwardmost perforation 4 in the annular tail member 2 and may even extend into the interior of the rear end lla of the projectile body 1. The rear section 2a of the annular tail member 2 which supports the fin assembly 3 is considerably longer than those in prior art constructions so that the chamber for accommodating the powder cartridge is enlarged. Ideally, the rear section 2a should be substantially the same length as the section of the tail member '2 containing the perforations 4.

The tubular powder member may be optionally enclosed within an outer sleeve I16 and an inner sleeve 17. Also, the forward end 10a of the tubular powder member 10 may be closed. A free annular space 18 is preferably provided between the rear end of the tubular powder member l0 and the externally threaded plug 6, the

free space l8 being enclosed by a sleeve 19. Preferably, a powder plug 20 is located at the forward end of the carrier sleeve ill in. the interior of the annular tubular powder member Ml. Forwardly of the powder plug 243 the space within the tubular powder member 10 is unoccupied and serves to reinforce combustion of the powder charge upon firing. Additional charges can optionally be positioned about the annular tail member 2 as indicated at 22.

In the embodiment shown in FIG. 2, similar parts are shown with the same reference numerals as in the first embodiment. The tubular powder member ltla of the powder cartridge 5a is pressed onto the carrier sleeve III to the extent of the limit step 13. In this case the tubular powder member lltlq is not closed at the front end by the powder material itself but rather is closed by a cover 23 of thin foil, paper or the like. The interior surface of the hollow space within the annular tail member 2 is provided with a sleeve 24 made of a combustible material. The sleeve 24 serves to cover the plurality of apertures 41 so that the powder member 10a which projects forwardly within the annular tail member is protected from any foreign matter which might otherwise enter through the perforations. 7

With the arrangements described, an improved projectile is produced which when fired has improved starting acceleration and thus a greater range.

Although particular embodiments of the invention have been described above, they are to be considered for the purpose of illustration only, and it will be appreciated that the invention is not limited thereto.

I claim:

l. A tail construction for a fin-stabilizing projectile for launchers, mortars and the like comprising a an elongated annular tail member having a tin assembly mounted on the exterior thereof and having a chamber therein and a plurality of perforations in J the wall thereof communicating with said chamber, and

b a powder cartridge mounted in said chamber for propelling said projectile,

c said powder cartridge including an elongated tubular powder member with a hollow interior space, an elongated annular carrier sleeve extending through said hollow interior space of said tubular powder member to support said elongated tubular powder member in said chamber in a position such that an annular air space is present between the exterior surface of said powder member and the interior surface of said perforated wall of said tail member and securing one end of said carrier sleeve to the rear end of said annular tail member,

d whereby upon firing said powder cartridge the hollow interior space in said powder member and the annular space between the exterior of said powder member and the wall of said annular tail member reinforce v combustion and gases are released through said perforations in the wall of said tail member.

2. A tail construction as defined in claim 1 wherein the forward end of said tubular powder member extends at least to the forwardmost perforation in aid tail member.

3; A tail construction as defined in claim 1 wherein said plurality of perforations are located in thewall of said annular tail member at a location forwardly of the location of said fin assembly, the length of the portion of said tail member containing said plurality of perforations being substantially equal to the length of the portion of said tail member supporting said tail assembly.

4. A tail construction as defined in claim 1 further comprising a frangible annular sleeve located contiguous to the interior of said tail member and covering said plurality of perforations to protect said powder cartridge from foreign matter until said powder cartridge is used.

5. A fin-stabilized projectile as defined in claim 4 wherein said frangible annular sleeve contiguous to the interior of said tail member and covering said plurality of perforations is combustible.

6. A tail construction projectile as defined in claim 1 wherein said carrier sleeve includes a portion at the forward end thereof having a reduced cross-section providing a stop along the exterior surface of said carrier sleeve to prevent said tubular powder member from sliding rearwardly beyond a predetermined point.

7. A tail construction as defined in claim 6 wherein the interior surface of said chamber at the rear end of said annular tail member includes helical threads therein, said one end of said carrier sleeve includes an outwardly extending conical portion, and said means for securing said one end of said elongated carrier sleeve comprises an externally helically threaded member for engaging the threads on the interior of said annular tail member and said conical portion of said carrier sleeve.

8. A tail construction as defined in claim 1 wherein said carrier sleeve includes perforations in the wall thereof.

9? A tin-stabilized projectile as defined in claim 8 further comprising a powder plug in the interior of said carrier sleeve. 

1. A tail construction for a fin-stabilizing projectile for launchers, mortars and the like comprising a an elongated annular tail member having a fin assembly mounted on the exterior thereof and having a chamber therein and a plurality of perforations in the wall thereof communicating with said chamber, and b a powder cartridge mounted in said chamber for propelling said projectile, c said powder cartridge including an elongated tubular powder member with a hollow interior space, an elongated annular carrier sleeve extending through said hollow interior space of said tubular powder member to support said elongated tubular powder member in said chamber in a position such that an annular air space is present between the exterior surface of said powder member and the interior surface of said perforated wall of said tail member and securing one end of said carrier sleeve to the rear end of said annular tail member, d whereby upon firing said powder cartridge the hollow interior space in said powder member and the annular space between the exterior of said powder member and the wall of said annular tail member reinforce combustion and gases are released through said perforations in the wall of said tail member.
 2. A tail construction as defined in claim 1 wherein the forward end of said tubular powder member extends at least to the forwardmost perforation in aid tail member.
 3. A tail construction as defined in claim 1 wherein said plurality of perforations are located in the wall of said annular tail member at a location forwardly of the location of said fin assembly, the length of the portion of said tail member containing said plurality of perforations being substantially equal to the length of the portion of said tail member supporting said tail assembly.
 4. A tail construction as defined in claim 1 further comprising a frangible annular sleeve located contiguous to the interior of said tail member and covering said plurality of perforations to protect said powder cartridge from foreign matter until said powder cartridge is used.
 5. A fin-stabilized projectile as defined in claim 4 wherein said frangible annular sleeve contiguous to the interior of said tail member and covering said plurality of perforations is combustible.
 6. A tail construction projectile as defined in claim 1 wherein said carrier sleeve includes a portion at the forward end thereof having a reduced cross-section providing a stop along the exterior surface of said carrier sleeve to prevent said tubular powder member from sliding rearwardly beyond a predetermined point.
 7. A tail construction as defined in claim 6 wherein the interior surface of said chamber at the rear end of said annular tail member includes helical threads therein, said one end of said carrier sleeve includes an outwardly extending conical portion, and said means for securing said one end of said elongated carrier sleeve comprises an externally helically threaded member for engaging the threads on the interior of said annular tail member and said conical portion of said carrier sleeve.
 8. A tail construction as defined in claim 1 wherein said carrier sleeve includes perforations in the wall thereof.
 9. A fin-stabilized projectile as defined in claim 8 further comprising a powder plug in the interior of said carrier sleeve. 